PLATE 3 
EXPLANATION OF FIGURES 
8 Part of mucosa in figure 1 enlarged. Middle of interval. > 624. 
9 An enlarged portion of the epithelium in figure 2. End of interval. Note 
the enlarged superficial epithelial cells. X 572. 
10 The upper part of the mucosa in figure 3 more highly magnified. Stage 1. 
The superficial epithelial cells are vacuolated. Under them is the beginning 
of the cornified layer. > 624. 
11 More highly magnified portion of epithelium in figure 6. After the shed- 
ding of the cornified layer. Stage 3. X 624. 
(Drawn by Miss Edna Fisher) 
448 
